| NTT ELECTRONICS CORPORATION Patent applications |
| Patent application number | Title | Published |
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| 20120106969 | Communications apparatus, multiplex communications apparatus, communications system, and communication method - A communications apparatus includes a transmitter that transmits signal light that is wavelength division multiplexed with other signal light and that is to be transmitted to an opposing apparatus, and a processor that is operative to change a frequency of the signal light to be transmitted by the transmitter based on detection results at the opposing apparatus and concerning variation in the frequency of the transmitted signal light. | 05-03-2012 |
| 20110304897 | Optical Semiconductor Module and Method for Assembling the Same - An optical semiconductor module in which displacement resulting from fixation of lenses is effectively corrected includes a first lens ( | 12-15-2011 |
| 20110262136 | OPTICAL DIGITAL TRANSMISSION SYSTEM - An optical digital transmission system of the present invention newly defines one second negative stuff byte in an overhead area for accommodation of the client signals with multiplexing into the OTU frame, newly defines one third positive stuff byte in a corresponding tributary slot in a payload area for accommodation of client signals with multiplexing, newly defines stuff control bits that is used for decision of the use of the second negative stuff byte and the third positive stuff byte in three different places in the overhead area for client signal accommodation with multiplexing, performs control by using the newly defined stuff control bits when accommodation of the client signal with the third positive stuff byte or the second negative stuff byte is required, and performs stuff control without using the newly defined stuff control bits when accommodation of the client signal by the third positive stuff byte and the second negative stuff byte is not required. | 10-27-2011 |
| 20110241150 | AVALANCHE PHOTODIODE - An electron injected APD with an embedded n electrode structure in which edge breakdown can be suppressed without controlling the doping profile of an n-type region of the embedded n electrode structure with high precision. The APD comprising a buffer layer with a low ionization rate is inserted between an n electrode connecting layer and an avalanche multiplication layer. Specifically, the APD is an electron injected APD in which an n electrode layer, the n electrode connecting layer, the buffer layer, the avalanche multiplication layer, an electric field control layer, a band gap gradient layer, a low-concentration light absorbing layer, a p-type light absorbing layer, and a p electrode layer are sequentially stacked, and a light absorbing portion that includes at least the low-concentration light absorbing layer and the p-type light absorbing layer forms a mesa shape. | 10-06-2011 |
| 20110229152 | Bit-Rate Discrimination Method and Its Apparatus - In the present invention, unlike a conventional circuit, discrimination is not made by integrating a logical code that includes “0” and “1” to some extent and produced from a random code, but repetition of an identical pattern of a well-known preamble signal added to a head portion of a signal is discriminated when a bit-rate of the signal is changed. More specifically, the repetition of the identical pattern is converted into a consecutive identical signal to generate the consecutive identical signal (having a length of tens bits to thousands bits). Although the consecutive identical signal is longer than a same-code continuation length included in the signal, and is shorter than a time constant necessary to the conventional circuit by about one to three digits. Therefore, an integration time can be shortened to the same degree as the generated consecutive identical signal length, and the bit-rate can be discriminated at high speed within a preamble signal receiving time. | 09-22-2011 |
| 20110170832 | OPTICAL TRANSCEIVER MODULE AND METHOD OF MANUFACTURING THE OPTICAL TRANSCEIVER MODULE - An optical transceiver module that is capable of being inserted into and removed from a cage includes a housing that houses a photoelectric conversion element, the housing having a guiding section formed along a front-rear direction, an operating lever that has an operating section and a lever-side contact section, the operating lever being attached to the housing in a rotatable manner about an axis of rotation; and a slider that has a wedge section that engages with a latching section provided to the cage, and a slider-side contact section that comes into contact with the lever-side contact section, the slider being guided in the front-rear direction by the guiding section, the lever-side contact section being located opposite the operating section with respect to the axis of rotation, and as the operating section is pushed rearward, the lever-side contact section pushes the slider-side contact section forward and the slider moves forward to a position where the wedge section is unlatched from the latching section. | 07-14-2011 |
| 20110122964 | Binary Arithmetic Coding Device - An object of the present invention is to provide a binary arithmetic coding device that allows real-time processing with a higher image quality. At a timing at which a ternary data string for a target bit is outputted, an updated coding range width and an updated range width of less probability are outputted. For that reason, while a binary conversion unit ( | 05-26-2011 |
| 20110064355 | WAVEGUIDE DEVICE AND MODULE - Excess optical power in a waveguide device is appropriately terminated. According to one embodiment of the present invention, the waveguide device comprises a termination structure filled with a light blocking material for terminating light from the end section of a waveguide. This termination structure can be formed by forming a groove on an optical waveguide by removing the clad and core, and filling the inside of that groove with a material attenuating the intensity of the light (light blocking material). In this manner, light that enters into the termination structure is attenuated by the light blocking material, and influence on other optical devices as a crosstalk component can be suppressed. With such termination structure, not only the influence on optical devices integrated on the same substrate, but also the influence on other optical devices directly connected to that substrate can be suppressed. | 03-17-2011 |
| 20110033193 | MODULATION METHOD, MODULATION PROGRAM, RECORDING MEDIUM, MODULATION DEVICE, AND OPTICAL TRANSMITTER - A modulation method according to the invention is applied to a modulation device in which a light source is driven by a differential signal while a modulation circuit and the light source are capacitively coupled. In the modulation method of the invention, when an average potential fluctuates at an input terminal of the light source, a potential fluctuation is externally provided using a control circuit such that a normal phase side and a reverse phase side become equal to each other in a time constant of the fluctuation in average potential, and transient states of the average potentials at the normal phase side and reverse phase side are equalized and cancel each other as in-phase components of a signal input to the light source, which allows an optical signal to be normally transmitted from the light source. The optical signal can normally be transmitted from the light source even before the average potentials at a normal phase input terminal and a reverse phase input terminal of the light source are stabilized. | 02-10-2011 |
| 20100322569 | OPTICAL MODULE - An optical module has a structure for reducing the stress applied to a package. The optical module is structured so that an end face of a waveguide ( | 12-23-2010 |
| 20100296766 | SEMICONDUCTOR OPTICAL MODULATOR - The present invention can provide an npin-type optical modulator that has a high withstand voltage and is easily fabricated. A semiconductor optical amplifier ( | 11-25-2010 |
| 20100188724 | WAVELENGTH-SELECTIVE SWITCH - A wavelength-selective switch with a switch unit having a lens array, a first lens and a beam expander, and a branching unit having a second lens, a diffraction grating, a third lens and a mirror, in which the switch unit and the branching unit are accommodated in independent casings, and a confocal point of the light transmitted through the first lens and the light transmitted through the second lens are arranged on a connecting surface of the casing of the switch unit and the casing of the branching unit. | 07-29-2010 |
| 20100163925 | AVALANCHE PHOTODIODE - In an electron-injection type APD, it is necessary to prevent a dark current increase and to secure the life time of the device. It is demanded to improve reliability of the APD with a lower production cost. With the InP buffer layer having an n-type doping region on the inside of a region defined by an optical absorption layer, a predetermined doping profile is achieved by ion implantation. Thus, electric field concentration in the avalanche multiplication layer is relaxed. Furthermore, a low-concentration second optical absorption layer is provided between the optical absorption layer and the avalanche multiplication layer. Responsivity of the optical absorption layer is maximized, and depletion of the lateral surface of the optical absorption layer is prevented; thus, electric field concentration is prevented. Preventing edge breakdown, the device improves its reliability. | 07-01-2010 |
| 20100105323 | Electric-Field Communication Device - A signal electrode ( | 04-29-2010 |
| 20100053720 | LIGHT SOURCE APPARATUS WITH MODULATION FUNCTION AND ITS DRIVING METHOD - A light source apparatus with modulation function has a wavelength conversion module ( | 03-04-2010 |
| 20100008626 | OPTICAL CHIP FOR ARRAYED WAVEGUIDE GRATING TYPE OPTICAL MULTIPLEXER/DEMULTIPLEXER CIRCUIT, WAVEGUIDE SUBSTRATE, AND METHOD FOR FABRICATING OPTICAL CHIP FOR ARRAYED WAVEGUIDE GRATING TYPE OPTICAL MULTIPLEXER/DEMULTIPLEXER CIRCUIT - An optical chip according to the present invention is formed into a projecting shape expanded toward either side at the center. A waveguide substrate has a layout in which arrayed waveguide grating type optical multiplexer/demultiplexer circuits, each having a curve direction of an array waveguide reverse to each other, are arranged in combination, and the optical chips are cut out of the waveguide substrate. A method for fabricating the optical chip according to the present invention can enhance an optical chip yield rate, and further, can fabricate an optical chip having the shape for stabilizing optical characteristics of the arrayed waveguide grating type optical multiplexer/demultiplexer circuit. | 01-14-2010 |
| 20090316742 | SEMICONDUCTOR LASER DEVICE AND DRIVING METHOD OF THE SAME - A semiconductor laser device according to the present invention outputs light while periodically varying the temperature of a semiconductor laser, an optical waveguide, or a diffraction grating, outputs light while causing the optical waveguide or the diffraction grating to mechanically and periodically vary, or causes return light, which varies periodically or non-periodically, to be incident on the semiconductor laser. Since the periodical fluctuation is applied to the temperature of the semiconductor laser, the optical waveguide, or diffraction grating, the periodical mechanical variation is applied to the optical waveguide or the diffraction grating, or the return light is caused to be incident on the semiconductor laser, the semiconductor laser carries out a multimode oscillation from a low output to a high output without shifting between a single mode oscillation and a multimode oscillation. Accordingly, the present invention can provide a semiconductor laser device having IL characteristics in which a current is proportional to a light output and a driving method thereof. | 12-24-2009 |
| 20090238266 | TRANSCODER - A category setting part sets a type of a decoded image based on characteristics of the decoded image which are fineness of the decoded image and an intensity of movement of the decoded image. A code amount setting part sets a target code amount of an output image based on the type of the decoded image. A quantization step value setting part sets a quantization step value of the output image based on the target code amount of the output image. A transcoder can set the target code amount of the output image depending on fineness of the decoded image. The transcoder can distribute the target code amount of the output image to a reference image and a predicted image depending on the intensity of movement of the decoded image. | 09-24-2009 |
| 20090237569 | TRANSCODER - A scene change detection part detects a scene change based on a characteristic amount of an input image. A target code amount setting part executes correction by a correction code amount on a target code amount previously set for suppressing variation of an output code amount around the time of scene change. A quantization step value setting part sets a quantization step value based on the target code amount. That is to say, a transcoder | 09-24-2009 |
| 20090174819 | MOTION VECTOR DETECTION DEVICE AND MOTION VECTOR DETECTING METHOD - It is an object to reduce an amount of calculation for motion vector detection and to prevent degradation in image quality. A motion vector detection device ( | 07-09-2009 |
| 20090009370 | TRANSCODER - A transcoder calculates a reference conversion factor on the basis of a ratio between a total target bit rate of a whole second stream and an total input bit rate of a whole first stream and calculates a coefficient of variation from the total target bit rate of the whole second stream and an average output bit rate of a converted second stream in the N period. Next, a quantization step conversion factor in the next (N+1) period is calculated by adding the coefficient of variation to the reference conversion factor. Then, a quantization step value of a second stream in the (N+1) period is calculated by multiplying a quantization step value of a first stream in the (N+1) period by the quantization step conversion factor. | 01-08-2009 |
| 20080304786 | Semiconductor optoelectronic waveguide - The present invention relates to a semiconductor optoelectronic waveguide having a nin-type hetero structure which is able to stably operate an optical modulator. On the upper and lower surfaces of the core layer determined for the structure so that electro-optical effects are effectively exerted at an operating light wavelength and are provided with intermediate clad layers having a band gap which is greater than that of the core layer | 12-11-2008 |
| 20080226298 | Optical Transmission System - The present invention has been achieved to provide a novel optical transmission system realizing high-speed optical transmission over greater distance by suppressing waveform degradation caused by mode dispersion and mode transition in a multimode optical transmission line. The optical transmission system of the present invention includes: an optical transmitter for transmitting incoherent light; an excitation mechanism for exciting a predetermined mode in the incoherent light transmitted from the optical transmitter; a multimode optical transmission line for transmitting the incoherent light transmitted from the excitation mechanism; a transmission mechanism for transmitting a predetermined mode in the incoherent light transmitted from the excitation mechanism; and an optical receiver for receiving the incoherent light transmitted from the transmission mechanism or the incoherent light transmitted from the transmission mechanism. | 09-18-2008 |
| 20080226290 | OPTICAL SIGNAL MONITORING APPARATUS, OPTICAL SYSTEM AND OPTICAL SIGNAL MONITORING METHOD - By reducing the number of PD arrays, and by simplifying the configuration of an optical power monitor in a WDM system, a miniaturized, cost reduced optical signal monitoring apparatus, optical system or optical signal monitoring method is provided. An optical power monitor | 09-18-2008 |
